15 replies to this topic

[baker_boy]

most minis front wheels are toe-ing in and they handle pretty well, but i thought... that when you see cars like touring cars there front wheels are toe-ing out quite a bit and they probably handle amazingly..so why cant we do that?
im prob chatting shizzle so if i am just tell me..

cheers

[The Matt]

Camber angle and toe-in/toe-out (tracking) are two different things

[koss]

I thought it was the opposite way round, mini toe out front wheel drive.
Rear wheel drive toe in.
Then again my mini has 1 1/2 degrees of toe in but its rear wheel drive

[Guess-Works.com]

Toe in/out (or tracking) is different to camber, which again is different to castor which is all about the angle of the hub..

Essentially, 0 degress toe is the 'ideal' as this means the wheel is running parallel to the direction of travel, therefore not wearing the tyre out...

But, toe out is said to improve 'grip' when cornering, but I believe too much toe out can induce oversteer (ie the tail stepping out), toe in I believe induces understeer which is safer for your everyday car...

The Toe at the rear of the mini works in a similar way with toe in (being the default) being safe and steady, whereas toe-out at the rear will indeuce a shopping trolley effect if too much...

Camber is the 'lean' of the wheel away from vertical, so -ve camber is the wheels sticking out at the bottom ( evident on lowered minis at the front ) and +ve camber (std for the rear) has the top of the wheel further out than the bottom.

on the other hand I may be talking complete Boll***s

[nmt_oli]

Sounds right to me John, and IIRC, cast is the difference in camber between 20deg turned left, and 20deg turned right. It to to with king pin inclination.

[baker_boy]

rite ok cool thanks, i may play with it a little to make it so its straight and not biased then see what happens trial and errors prob the best way, thanks guessworks

[fikus01]

i think as std minis have 1.5 degrees of toe out and apto 1degree of negative canmber at the front. rears shud toe in and have upto 3 degrees of positive camber !!

[mini25]

camber is the angle of the wheels on a vertical plain

camber is the angle of the wheel, always want the wheel to angle inwards at the top, means wen the car leans over in a corner the car is steady on the flatg of the tyre not the edge, this applies front and back

toe is the angle of the wheels on horizontal plain

alwasy want toe in on the rear as this basically gives the rear more grip and toe out will create the shopping tolley effect, toe in on the fron is steady and is what all road cars are set to, but is slightly twitchy compared to toe out, toe out will mean the car is quicker to square up onto a straight after a corner, toe in means it is quick to turn in

and caster is another story

[mini25]

obviously u dont want too much of any of these, 5degree ABSOLUTE max but u need around 1degree of everyhting on any car

Edited by mini25, 21 March 2007 - 02:29 PM.

[icklemini]

Bit more to the topic, based upon setting handfulls of road and race cars up:

Camber describes the angle at which a wheel sits in a vertical plane. Imagine looking at the wheels as you stand in front of the car. If the top of the wheel is angled inwards, towards the car then the wheel has negative camber, similarily if the top of the wheel is angled out, away from the car then the wheel has positive camber. If the wheel sits vertically then it has zero camber. Camber is measured in degrees. On a Mini it is altered at the front by adjusting the length of the bottom arm - at the back the radius arm outer pivot point is moved up or down.

Castor Angle is the angle to the vertical plane on which the steering axis sits as viewed from the side. In other words imagine looking at the side of the front wheel, the Castor Angle is the angle an imaginary line makes that is drawn through the centre of top ball joint and down through the lower suspension arm ball joint. Castor Angle determines the amount of self-centring the steering will have, influence the straight-line running and influence the camber change when cornering. On a Mini the length of the tie-rods effect the Camber angle

Alignment - Toe describes the angle at which a wheel sits on a horizontal plane relative to the longitudinal axis of the car. In other words imagine looking vertically down on top of a wheel mounted on a car, if the front of the wheel is angled inwards more than the rear of the wheel then it is said to have ‘toe-in’, if it’s the other way around then the wheel is said to have ‘toe-out’. If the wheel is parallel with the longitudinal axis of the car then it has zero toe. Toe can be measured in degrees or measured as the distance difference between the front of the wheel rim and the rear of the wheel rim. Total Toe is the overall distance for a pair of wheels whereas Individual Toe is half the Total Toe and relates to individual wheels. This is adjusted at the vront via the steering arem track rods, at the back its adjusted by moving the radius arm pivot front/back (which can then effect corner weights marginally...)

Ok, with that explained:
The front wheels can be aligned, the rear can be aligned - but they need to be aligned front-back.
As standard the rear of the mini is 'fixed' so you can adjust the front to the back. Now if the back is not square then its going to end up all over the place!
The easy solution is to get some camber/tracking brackets for the rear frame. The rear geometry can then be setup. If you have loads of time you can make shims up, but its very laborius.

Setting the front tracking is quite easy as long as adjustments are made to both sides and are equal - this ensures the rack stays central, now its further complicated by having (a) bent steering arms, (b) a rack that isnt centred © a rack that isnt square in the shell.

The full lock-to-lock angles needs to be checked on Turnplates and with the front tracking parallel the heel and toe lock angles should be comparable on both sides, If not, then something aint right!. - If the arms are bent, then they need replacing. If the rack isnt centred then centre it!, and finally if the rack isnt centred in the shell (and cant be shifted to its correct place for whatever reason). then you have to to judicious offsetting of the trackrod adjustments (that is have one side wound in more - the other side wound out - hard to explain, easier to show) Basically you aim is to get the heel and toe turn angles pretty much the same.

Once the rack is 'central' and the same steering angles are occuring lock to lock. then the fronts can be finally aligned.

Castor angles need to be the same on both front wheels - if not one wheel will 'drag' and cause the car to pull. Castor needs to be set and adjusted with the front alignment parallel.

Camber and castor can effect each other. - The fixed 'negative camber arms' only alter the tolerance that is already in your subframes - It is usual to have different cambers on each side of the car due to manufacturing tolerances - fitment of these arms will alter this figure by the same amount on both sides. - 'Hand selection' of bottom arms are needed here.

Also check the bottom arm pin - these can bend.

Rear tracking: well on a road car you'd be brave/stupid to have toe out, toe out at the back massivly increases oversteer. I setup the circuit racers with toe out, but never a road car.

Settings,

Well as standard the mini has:
Front camber = 2degs positive +- 1 deg
Front castor = 3degs positive +- 1deg
Front toe = 1/16" toe out
Rear camber = 0.5 to 2.5 degs positive
Rear track = 1/8" toe in

good 'baseline' settings do depend on the wheels in use,
10" wheels you can run more neg camber on the front that you'd want with 13" wheels
I would set the rear track to 1/16" toe in to parallel max.
rear camber rule of thumbe here is to have it a degree less than at the front. (so if you have -1.5deg front, run the back at -0.5deg)

hth,
Dave

[Scarface]

ye road car depending on setup personal preference etc id say:

FRONT:
Camber: 0-2neg
Toe: out 1-3mm
Castor: 2-5 deg

REAR:
Camber: 0-1neg
Toe: In 0-1mm

Normally the bigger the wheel/lower the sidewall profile the less camber u use,
Toe out at the rear is for track cars, parrallel meaning no drag, but slight toe in can help
stability,
Castor as said is what going on as ur turning, think if i remeber rite the higher u go the
more grip is achieve but the worse the handling gets i.e heavy steering!

[EdMountain]

How to you set up your camber and toe?

[Swift_General]

Camber - By adjusting the length of the bottom arm, you can get adjustable arms or alternatively fixed arms that are longer than standard thus giving you less positive/more negative camber.

Toe - Adjusting track rod ends.

Be aware that if you adjust the camber this will also change the toe so this will need re setting.

[Spider]

I think that all the relevant descriptions have been well covered above.

 

I actually prefer to run O⁰ Camber on the fronts and around 4 - 5⁰ Caster up there.

 

But setting the wheels in this way we have as best Traction as you will get for Accelerating and Braking, then on the turn in's the Wheel will naturally dial in Camber the more it turns due the the Caster Angle.

[harrythehat]

^{Know its going back a while to this thread}

^{\but its as easy as a ball of string}

^{did mine this arvo}

^{wrapped string to exhaust as anchor}

^{went from back wheel centre to front wheel centre  under front valance to other front wheel  then to back wheel pulling tautish then tying of to  inside edge mudguard}

 

^{Immediately it shows toe in on rear wheels gaps were pretty equal}

^{adjusted each front wheel  till string just bounced of rear edge of tyre leaving just a tad of positive camber}

 

^{only takes a few minutes to set up so if your not happy with ride easy to do again}